1. Field of the Invention
The invention relates to an electrical connector, and more particularly, to a memory module socket for releasably securing a memory module, such as single in-line memory module. The subject matter of the invention constitutes an improvement for the latch of the socket and for a mounting peg to retain the insulating housing of socket in mounting aperture of printed circuit board.
FIG. 1 depicts a typical example of socket 40 for securing a memory module 31 to a printed circuit board 32. The socket 40 has an insulating housing 41, which is preferably injection molded from electrically insulative and temperature-resistance plastic. An elongated socket 42 is located along the longitudinal axis of insulating housing 41. A plurality of slots 43 are in sequence located along and perpendicularly in relation to the elongated socket 42. A plurality of electrically conductive contact elements 57 are respectively inserted into each slot 43. On the left end of this insulating housing 41, a retention post 44 integrally formed to extend upward from the insulating housing 41. A securing projection 45 extends transversely from the upper end of the retention post 44 and perpendicular to the longitudinal axis of insulating housing 41. To the left of the retention post 44 is a latch member 56, which perpendicularly extends upward from the insulating housing 41. Located on the upper end of latching member 56 is a latching projection 46 that extends toward the other end of insulating housing 41. The right end of insulating housing 41 is provided with the same features as the left end of insulating housing 41, but symmetrically arranged: a retention post 47 with a securing projection 49, and a latch member 48 with a latching projection 50.
Each end of the single in-line memory module 31 includes securing holes 58 and 59. The single in-line memory module 31 is inserted into the elongated socket 42 of insulating housing 41 and each upper end edge of in-line memory module 31 slides over the latching projections 46 and 50 to allow securing holes 58 and 59 to be received within securing projections 45 and 49, respectively, which secures each edge of the single in-line memory module 31 with latching projections 46 and 50.
To release the single in-line memory module 31, push outwardly each of latch members 48 and 56, to force each of latching projections 46 and 50 to disengage from each edge of single in-line memory module 31. The single in-line memory module 31 now disengages from the elongated socket 42 of insulating housing 41.
At each end of the insulating housing 41 are mounting pegs 51 and 52, each perpendicularly extending downward wherein mounting peg 51 has a smaller diameter than mounting peg 52 for inserting into mounting apertures 53 and 54. The mounting apertures have different inside diameter from each other to prevent the insulating housing 41 from being incorrectly mounted.
However, two major problems are associated with the single in-line memory module and socket. The first problem is that the portion that engages latch members 45 and 56 with the insulating housing 41 is liable to get cracked or even broken. The second problem is when each of the mounting pegs 51 and 52 of insulating housing 41 are inserted into the mounting apertures 53 and 54, respectively, of printed circuit board 32 they must be welded within a soldering stove. Specifically, the contact pin 55 extending downwardly from the slot 43 will be attached to the printed circuit board 32 by welding. During the soldering process, liquified solder will flow upward to push the insulating housing 41 upward, increasing the spacing between the insulating housing 41 and printed circuit board 32, resulting in the failure of insulating housing 41 to be firmly secured to the printed circuit board 32.
To overcome the first problem, U.S. Pat. Nos. 4,713,013, 4,832,617, 4,850,892, 4,850,891, 4,737,120 and 4,995,825 relate to disclose an improvement with respect to the latch member, specifically metallic latch members are fabricated in place of conventional plastic latch members, thus making the latch members more durable. However, they fail to solve the second problem, firmly securing the insulating housing to the printed circuit board, because the outer edge of each mounting peg extends downward from the insulating housing and is fabricated in a cylindrical shape.